Periodontal diseases afflict many individuals and are the major cause of tooth loss in adults. Recent evidence from several laboratories has indicated that specific bacterial species are responsible for the initiation and progression of periodontitis. A recent large scale study of patients with insulin dependent diabetes mellitus (IDDM) has shown that the prevalence of periodontitis in young IDDM patients is 6-10 fold higher than that seen in nondiabetic subjects of similar age. Because periodontitis has been traditionally associated with older age groups, IDDM children are not adequately screened for periodontitis. Early diagnosis and treatment of periodontal infections in IDDM patients are important because infections in IDDM patients often increase insulin requirements. Furthermore, treatment for periodontal infections can result in significant post-treatment reductions in insulin requirements. Although they are at high risk, little is known about the microbiological or immunological aspects of periodontitis in IDDM patients. The proposed project is a detailed cross-sectional and longitudinal study of a large IDDM patient population. IDDM patients at the Joslin Diabetes Center, nondiabetic siblings and unrelated nondiabetic subjects from the dental clinic at Tufts University will be compared for the incidence and severity of periodontitis by conventional clinical examination. These groups will also be compared for the microbial species associated with health and disease activity and the serum and salivary antibody responses to these species. IDDM patients with periodontitis will be monitored and subgingival plaque samples from active periodontal lesions will be sampled and cultured by the specific pathogen method. The following species will be isolated and enumerated: Actinobacillus actinomycetemcommitans, Bacteroides, Capnocytophaga and Streptococcal species as well as Camphylobacter consisus, Eikenella corrodens, Fusobacterlum nucleatum and Wolinella recta. Serum and salivary antibody levels of individual isotypes to each microbial species will be measured by enzyme-linked immunoabsorbent assays. The clinical, microbiological and immunological data will be correlated. On the basis of these data, a diagnostic screening test for periodontitis in IDDM patients will be developed and used in clinical trial. These studies will hopefully provide insights into the pathogenesis of periodontitis IDDM patients, which may be relevant to nondiabetic populations. Furthermore, these studies may validate the usefulness of a diagnostic test for periodontitis in a young, high risk population.